eimecke



2 Sheets-Sheet 1.

" (No Model.)

on, o. sa W. BIMEOKE. DOUBLE ACTING HOTIR ENGINE.

Pate d 'Jan.2, 1883-.

(No Model.) 2 Sheets-Sheet 2.

G., 0. sv-W. EIVMECKB. f DOUBLE ACTING EOT AIR NGINB.

1,' mec N. PETERS. Phatwulhngmpher, wnhngmn. D4 C.

UNITED STATES PATENT OFFICE.

GUSTAV EIMECKE, OTTO EIMEGKE, AND WILHELW EIMEUKE, OF BRUNS- \VIGK, GERMANY, ASSIGNORS TO SAMUEL SUDHElM, OF OASSEL,

PRUSSIA, GERMANY.

DOUBLE=ACTING HOT-AIR ENGINE.

SPECIFICATION forming part of Letters Patent No.- 270,036, dated January 2, 1883,

l Application filed January 6, 1882. (No model.)

To all whom it 'may concern Be it known that we, GUSTAV EIMECKE, O'rcro Einsam, and WILHELM EIMECKE, subjects ot' the Duke of Brunswick, and resi- 5 dents ot' Brunswick, in the Dukedom of Brunswick, German Empire, have invented certain new and useful Improvements in Hot-AirEngines; and we do hereby declare the following to be a i'ull, clear, and exact description of the 1o same, reference heilig had to the accompanying drawings, forming part of this specication, and to the tiguresaud letters of reference marked thereon.

This invention relates to that class of hotair engines in which one end of the working cylinderis arranged to be heated by a furnace, while the other end is by suitable means kept cool or at a comparatively low temperature, the air within the cylinder being changed from 2o one end to the other alternately by the action of a displacer, which is caused to change its position within the cylinder in accordance with the movements ot' the piston.`

The objects ot' the invention are to provide 2 5 a simple and accurately-operating combination of devices for eliectingl the changes of position of the displacer; to prevent the undue heating of the displacer, and a consequent disadvantageous communication ot' the heat there- 3o by to the air in the cold end ot' the cylinder;

. to obviate the hitherto existing reta-rdng effect ot` partial' vacuum and compressions during certain portions of the stroke of the piston,

and to insure an evenness of speed and force in the operation of the engine.

With these objects 1n view the invention consists in certain novel constructions and combinations ot devices, which will be hereinafter described with referenceV to the accom- 40 panying drawings, in which- Figure l is aside elevation ot a hot-air engine constructed according to my invention. Fig. 2 is an end elevation ot the same, the view being taken in the direction indicated by the arrow at the leftof Fig. l. Fig.3 is a view mainly in vertical section on the line :c a: of Fig. 2. Fig. 4 is a detached view of devices for operating a valve to relieve the cylinder ot' parts as when the piston is .commencing the latter halt' of its instroke. Fig. 7 is a detached top view of a ring forming .a part ot' the piston and containing air-passages, the ar rangement and purpose ot' which will be hereinafter explained. Fig. S is an edge view of' 6o the said ring. Fig. 9 is a diametric section of' the piston and attachments,illustratinga modi- Y tied'arrangement of airpassages for permitting access and egress of air to and from the cylinder through the piston. Figs. l0 and l1 65 are views mainly in section at right angles to the plane of section in Fig. 9, illustrating further the modified arrangement ot' air-passages and showing the valves controlling the same. Fig. l2 is a vertical section, and Fig. 13l a 7 o transverse section, showing the cylinder provided at its side with a direct-acting slidevalve forpermitting access and egress of air; and Fig. 14 is a vertical section, and Fig. 15 a side elevation ofthe cylinder, showing the same provided with a rotary slide-valve. for the same purpose.

Referring to Figs. l, 2, and 3, the letter F designates the working cylinder, the lower portion of which is arranged within a furnace, B, 8o while the upper portion extends through a cold-water reservoir,D, mounted on pillars E', provision being thus made for heating the lower and cooling the upper portion of Vsaid cylinder. t i 8 5 l? is the piston, which plays in the cylinder l F, and Q is a connecting-rod by` which the piston is connected to the crank-pin of a crank,

C, which is fixed upon one end ot' a driving-- shaft, U, mounted in bearings at the top of' 9o standards O 0, standing upon the top plate of reservoir D, said shaft carrying the ily-wheelA Y and the belt-pulley y. rl`he piston Pis provided with a hollow piston-rod, M, through which plays snugly a rod,`I, extending into the cylinder and carrying thereon the displacer H,

the particular construction of which will be presently described and explained. The piston-rod plays through a guide-bearing, L, supported ina frame, L', mounted upon the upper end of the cylinder.A v

The upper end of the rod Icarries a crosshead, W, to which is pivoted one end of a link, V, the other end ol which is pivoted to the end of an arm, T, projecting laterally from a short shaft, E, mounted in. bearings on standards e c, the feet ot' which are secured to a base-plate attached to the top plate of reservoir D.A

Projecting upwardly from the shaft E is an arm, S, the upper end of which is pivoted to one end of-a link, It, having its other end pivoted on the crank-pin of crank C, said pin being long enough to properly hold both the `said link an'd the connecting-rod Q.

The main operative parts ofthe engine have now been described, and to cause their operation a tire must be kept up in the furnace B and a' constantsupply ot cold water maintained in the reservoir D and surrounding the upper portion of the cylinder F. The supply of cold Water is provided by a pump, y, located in the reservoir, and having its plunger-rod connected with an eccentric, a, on the shaft U, an overflow-pipe, Z, carrying off the surl'acewater. To start the engine al'ter the lower part of the cylinder has become properly heated, the fly-Wheel is turned by hand until the piston is at the limit of its instroke and the displacer elevated. The air, becoming heated and expanded in the lower portion of the cyl-inder, will then force the piston upward. It will be seen that when thepiston rses in the cylinder rotary motion will be communicated to the shaft U through connecting-rod Q and crank C, and at the same time a rocking motion will be communicated to shalt E l'rom crank C through link R and arm S, causing the shaft E to vibrate the arm T, which, through the link V, causes a vertical reciprocating motion ofthe rod I through the hollow pistonrod M, the movement of the rod l being so timed that it` will carry the displacer H alternately to op posite sides of the cylinder, to cause changes of the bulk of the air therein with proper relation to the movements of the pistonthat is, when the piston commences the upper half of its outstroke the displacer begins to descend, displacing the hot air from the lower portion ot the cylinder and causing it to llow up between the displacer and cylinder to the upper portion of the latter, where it will become cooled and lose its tension so far that its resistance to the instroke of the piston will be overcome by the momentum of the ily-wheel. The cooling of the air will also produce a tendency toward a vacuum, which will enable the external pressure upon the piston to assist in impellin'g it through the instroke. The displacer continues to descend until the piston has completed the first half off its instroke, and then begins to ascend, displacing the cooled air from the upper portion of the cylinder and driving it to the lower portion, where by the time the piston completes its instroke it will have become heated and eX- pand to such a-degree as to force said piston upward again on its outstroke at the proper time, in which, as already explained, the displacer will begin to descend and repetition ot' the actions, as described, will continue as long as the opposite portions of the cylinder are respectively kept hot and cold. Motion may be transmitted from the engine to other machinery by a belt passing aroundthe pulley y in the usual manner.V Y' Y Y Y Y Y During the operation'of the engine variations in the furnace-heat are liable to produce increase or decrease of pressure in the cylin der, and leakage of air from the cylinder may so reduce the volume therein that its expansion will not give full force to the piston on its outstroke. To provide against such occurrences an equilibrator or air4reservoir, p, is arranged alongside the furnace and connected with the upper portion ofthe working cylinder by means of a pipe, o, in which, at o', is arranged asuitable valve, which may be opened and closed as required by connections with a governor, G', in the usual manner. When the pressure in the cylinder, and consequently the speed ot' the engine, vis too great, the governor, being connected by bevel-gears with the driving-shaft, will operate in the usual manner and through the intermediate connection open the valve -o', thus permitting a portion of the air to escape from the cylinder tothe equilibrator or reservoir p, and when through leakage or otherwise the volume of air in the cylinder becomes so far reduced as not to act et'- ticiently upon the piston the speed of the engine will be reduced and the governor act in the opposite direction to again open the valve o and permit a sufficient supply ot' air to enter the cylinder to restore a proper workingvolume.

In the partly-sectioned view, Fig. 4, are illustrated the connecting devices between the governor and the valve. The sleeve l plays vertically upon the stem l', and has pivoted to its upperend the ball-arms Z2 l2, the inner ends of which bear upon the top ot' the stem. The sleeve is circuml'erentially grooved at Z3, and into the groove project the pins from the embracing prongs of the bifurcated lever h', which is fulcrumed at the top of an arm, g. Depending from the lever h is a rod, h2, connected atits lower end with a link, fm,- which is pivoted to one end of a lever, a, the other lend ofwhich may be connected to a valve to open and close the same.

The displacer H is formed of hollow airres tight cylindrical sheet-metal sections It h h,

each having a tubular passage through its center to lit loosely around the rod I. The lower section rests upon a supportingplate, t', carried by the rod I, and the sections are separated from each other by intervening spaces, each of the upper sections resting upon slight atomes t s spurs It, projecting from the top of a next lower section. By this construction it will be seen that the heat will he very slow inv trailsmission from the-bottom section'to those above it, and when the top section enters the upper portion of the cylinder it will remain cool, notwithstanding that the bottom section is subjected to a very high heat, and the air in the upper portion of the cylinder will not be heated, as by old forms ot' displacers.

At the latter part of its outstroke, in an airengine as ordinarily constructed, the piston,

in enlarging the air-space of the cylinder, pro

duces a partial vacuum, which has a serious retarding effect, and a similar eft'ectresults from the compression of the airin the cylinder during the latter part of the instroke. In order to obviate the retardation resulting from 'such partial vacuum and compression,we provide ourengine withan automatic relief-valve, which at proper times will perrnitairto escape from the cylinder as required.

Referring to Figs. 5 and 6, the piston P is shown as formed ot' a central portion, p2, from the-bottom of which projectsatlange, p3, which iitsthecylinder. Thisdangeisrecessedaround its upper edge, as shown at p, and from this recess oblique passages 115 lead inwardly and downwardly through the flange. Upon the top of the liange is arranged a. flexible. packing-ring, t, the outer margin of which is folded down and extends partiallyacross said recess,

the Hap or folded portion being thin enough to have a slightlateral play in said recess. Upon this packing-ring rests-a metallic ring, s, a

plan View of which is shown in Fig. 7 and an edge View in Fig. 8. This ring hasan annular recess, s', extending downwardly from its upper surface, and from the bottom of this recess radial passages f lead through the jing and intersect oblique grooves m'rr', formed across its periphery.

Upon the top of thering s is placed a-ilexible packing-ring', t', and upon .the top of this packing-ring is placed anannular cover-plate, r', which is recessed around its lower edge/,and upwardly into 'the recess is folded the margin ofthe packing-ring t,in the same manner that the packing-ring t is folded into the recess of ilange p3. The cover-plate has formed through it a vertical passage, r2, which communicates at its lower end with the annular recess s' in the ring s, an aperture being cut in the packing-ringt to permitsuch communication. The upperxend of thc passage r2 connects with a port,"d, formed through the seat ct' of a slidevalve, ct, arranged to play in a valve-box, c, mounted upon the top plate, r', and having an opening in its-top. A port, el', is also formed through said valve-seat, and communicates at s its lower end with a passage,e2, which isformed through the top plate, fr', ring s, ilangep, and the intermediate packing-rings. The slidevalve a has its rod a3 pivoted to it at one end, the other end ot' said rod being pivoted to the connecting-rod Q, so that the vibrations of the connecting-rod will communicate areciprocating motion to the valve. t

ln Fig. 5 the-piston is represented as commencing the latter half of its outstroke, at which point of its movement it begins to draw a vacuum, which would impede its motion; Vbut at this point the valve a has been moved to open its port d, and thereby estab- `lish communication between the cylinder-space below the piston and the external air., so that air enters through the valve-box c, port d, passa gerz, annular recess s ,lateral passages ff j', and grooves xxz,and,tbrcing the iapofthe packing-ring t inwardly, passes through the recess p4 and oblique passages p5 to the space below the piston, thus counteractingthe tendency toward a vacuum, In Fig. (i the Ypiston is represented as commencingthe latter halt' ol' its insti-oke, at which time it would com- 1mence to produce a compression of the air in `the cylinder, and be thereby retarded were such an effect not provided against; but; at this point of the movement of the piston the bridgeshaped slide-valve a. has been moved to open the port cl' and passage e2, and airis thus permitted to escape from the cylinder and through the valve-box in sniijcient quantities to pre- Vvent any resistance to the piston by compres- ;sion of air below it..

n order tofurther facilitate the escape and ingress of air, additional oblique grooves, a?,

are formed at intervals about the periphery of ring s and intersect additional lateral passa ges,

When' f', leading from the annular recess s. air enters through the valve-seat it will,l be'- sides passing through the annular passage s and lateral passa ges f, also llo w around th rough said annular passage and underthe packing- 'ringt tothe additional passagesf', and thence `down through'tlie additional grooves wz, forcling aside the flap ct' packing-ring t and enter-` ing the cylinder through additional oblique passages, p5, in the ilange p3.

It will be-seen thatthe bridge-valve, while opening port d', also puts it in communication with port d, and a port-ion ot the air escaping from the port d may pass down through port d and passage lr2 to annular passage s', and,

following said passage around, it will lnd exit` through the additional passages j", tlie upper portions of additional grooves, :r2,`and, forcing aside the flap of packing-ring t', will escape throughthe recess in the cover-plate r and der-Wall,so that they will prevent the further passage of such air toward the oblique grooves, and no air, therefore, can pass these liaps unless it comes in the proper direction, as heretofore described. v

lIO

In Figs. 9, 10, and 1l the piston Phas its periphery unbroken except by the formation of a seat for the ordinary packin g-rin g. From the piston-rod M, however, there projects a holthrough the piston.

low trunnion, p7, the passagel m2 through which is closed at its outer end, but connected at its inner end with a passage, 19B, formed From the passa-gem2 ra'- dial passages p9 and p10 extend divergently through the trunnions,'said trunnions being `ontstroke, the passages p9 of the trunnion and q? ot' the collar q are in line and the external air-pressure will open checkvalve Q3 and air will How into the cylinder through said passages and the passages m2 in the trunnion and vp8 in the piston, thus counteracting 'the tend ency toward the formation of a vacuum inthe eylinder.- When the piston begins the latter half of its instroke, as shown in Fig. 1l, the passagesp' of the trunnion and g3 of lthe collar are in line, and airwill flow from the cylinder through-the passages p3 ofthe piston and m2 and p10 of the trunnion, and thence through the passage g3 ot' the collar, and will force the valve Q4 open and escape in sufficient quantity to prevent any retarding eifect upon the piston by compression.

In Figs. 12 and 13 we illustrate another modified arrangementof the relief-valve. Upon the side of the cylinder F is formed a valveseat, a, having a port, c4, formed through it to the interior ofthe cylinder, and a corresponding port, e5, through thetop plate, c6, of the valve-casing connects with an air-pipe, di. A direct-acting slide-valve, N, plays between the top plate and the valve-seat, and has two ports, n2 and n3, which may be alternately brought in line with the ports c4 and c5. The slide-valve is pivoted to a rod, the upper end of which may be connected with an eccentric on the driving-shaft, so timed that one of the ports a2 or a'will be opened 'to permit the passage of air when the piston is beginning the lasthalf of its outstroke and the other when it is beginning the last half of its instroke, l'or the purpose already stated.

In the modification of the relief-valve shown in Figs. 14 and l5 a seat, a5, forthe rotary valve N' is formed on the side of the cylinder, said seat having two through-ports, a5 and a6, diametrically opposite each other, and lcommunicating -with the cylinder. The\rotary arrangements of devices shown and described, Y

but may vary the same in any manner within the practice of engine-building, or by the substitution of equivalents, while not departing from the true spirit and scope of our invention.

Having thus described our invention, we claim-k 1. The combination, with the cylinder, the piston having the hollow piston-rod, the displacer within the cylinder, t-he rod-I, carrying said displaceratitslowerend,thelink V, arm T, and suitable intermediate connections for communicating a-vibratory motion to said arm from the crank C, of the driving-shaft connect'ed with the piston, substantially as described.

2. In a hot-air engine, the combination, with the cylinder and piston, of a relief-valve, arranged to open when the piston begins the latter part of-both its ontstroke and instroke, and. devices connected with the moving part of the engine for automatically and positively operating said valve, for the purpose set forth.

3. In a hot-air engine, the combination, with a working cylinder, ot a connected air-reservoir and an au-tomatically-operating valve, arranged t^o establish communication between the cylinder and reservoir at proper times, sub

stantially as described, and for the purpose.

set forth.

4. The combination, with the cylinder, airreservoir or equilibrator, the connecting-pipe, and valve arranged therein, of the governor operated by the driving-shaft, and suitable intermediate connections between the valve and the governor for operating said valve, substantially as described.

1n testimony whereof we have signed our names to this specilicatiou vin the presence of two subscribing witnesses.

GUSTAV EIMECKE.

OTTO EIMEGKE.

WILHELM EIMEGKE.

Witnesses:

WILLIAM U. Fox, Jous. KRAGKE. t 

